I will not clutter up the topic. I'll wait for the corrections. In general, I have a hard time compiling the App with GCC. GCC enforces static headers in the APP otherwise the information is duplicated with libsvt.

Svt encodes to raw hevc streams on my system, so I have to mux it and set framerate there.
The fps parameters on the cli are (I guess ) only to specify framerate of the input for things like calculating bits per second (so it needs to know how many frames in a second ).

I don't know, but do raw elementary hevc streams even have a fps field somewhere ?